One or more spools containing a printing ribbon of the type involved herein is per se old. For example, see U.S. Pat. No. 3,819,026. Ribbons of the type disclosed in said patent have been blister packaged in a conventional manner and shipped by air freight. When such packaged ribbons are received at the distination, the inside surface of the package is discolored and/or contains a film of ink. Such packages are unsightly and are rejected by customers as being defective.
After studying all aspects of the manufacture, packaging and shipment of such ribbons, I have concluded that such ribbons are not defective. The spools contain a reservoir of ink. The reservoir of ink is hermetically sealed and can only communicate with the ribbon by way of a pad which is exposed at its outer peripheral portion. I have concluded that during air shipment, the decrease in atmospheric pressure causes the ribbons to bleed. I have found that the problem created by bleeding of the ribbons can be solved as disclosed hereinafter.